Apparatus for conveying particle-form material



April 19, 1960 R. w. CURTIS 2,933,349

APPARATUS FOR CONVEYING PARTICLE-FORM MATERIAL Filed July 2, 1957 2 Sheets-Sheet 1 INVENTOR. Robert W. Curris i BWVLMM i ATTORNEY April 19, 1960 R. w. CURTIS 2,933,349

APPARATUS FOR CONVEYING PARTICLE-FORM MATERIAL Filed July 2, 1957 2 Sheets-Sheet 2 FIG.2

45 mtjmmmmmm 3mm]- 37 L8] 47 27.4 m ?!!|N| 2 INVENTOR. Roberr W. Curfis BY Wm ATTORNEY United States Patent 2,933,349 I APPARATUS FOR CONVEYING PARTICLE-FORM MATERIAL Robert W. Curtis, Alliance, Ohio, assignor to The Bahcock & Wilcox Company, New York, N.Y., a corporation of New Jersey Application July 2, 1957, Serial No. 669,557

4 Claims. (Cl. 302-64) 7 The present invention relates to apparatus for the transportation of particle-form solid material in a high pressure fluid medium, and more particularly to a lateral wear resistant fitting in a fluid lift apparatus used for the transportation of particle-form solid materials.

In the transportation of particle form solid materials in a fluid lift medium from a lower to a higher elevation, the solids have a tendency to erode the confining wall of the lift tube, particularly at the tube bends.

In general, two different types of fluid lift apparatus are presently in use, characterized by the density of the mixture of fluid lift medium and solids being transported. One type of fluid lift apparatus utilizes a light phase mixture wherein high velocity flow mediums are used and the medium actually entrains the solids. In this type of mechanism, the density of the mixture of solid-s and lift medium is relatively low. Another type of lift mechanism utilizes a dense phase mechanism where a relatively small volume of high pressure fluid is used. In the dense phase mechanism, the velocity of the mixture passing through the lift pipe is relatively low with the solids moved as a generally solid mass. In both types of lift mechanism, the erosion of the solids on the inner surface of the lift pipe is particularly bad wherever the flow direction of mixture movement through the pipe is changed.

According to the present invention, a lateral fitting is provided for use in the lift pipe, where the fitting is utilized to effect a change in flow direction of the mixture passing through the flow pipe. The wear occasioned by theerosion of the particle-form solid material on the pipe is minimized by the use of the lateral fitting of the present invention. This is accomplished by providing an arrangement for the accumulation of a bed of particleform solids so that the solids rising in the lift pipe impinge on the bed of solids during the operation of the apparatus before the shot is changed in its flow direction. In impinging on a bed of solids, the moving solids will be changed in their direction of movement without eroding the confining walls of the lift pipe in the area of the change of flow direction. The bed of particle-form solids is maintained in a pocket in the lateral fitting during operation of the unit only, so that when the unit is shutdown, the bed of particle-form material falls from the pocket into a lower portion of the system with the reduction of the fluid lift pressure. The bed is re-established in the pocket of the lateral lift fitting upon the resumption of flow when the bed is reconstituted with a new mass of solid particle-form material.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptiye matter in which I have illustrated and described a preferred embodiment of the invention.

.. exchange apparatus being cleaned. In the arrangement "ice Of the drawings:

Fig. 1 is an elevation, partly in section, of a fluid lift mechanism incorporating the present invention and installed in connection with a shot cleaning system;

Fig. 2 is an enlarged View, partly in section, of the inventive portion of the shot cleaning system shown in Fig. l; and

Fig. 3 is a section taken on the line 33 of Fig. 2.

While the invention is illustrated as applied in the lift line of a shot cleaning installation, as associated with a heat exchange apparatus or vapor generator, the invention is applicable to any lift mechanism using a fluid lift medium with any particle-form solid materials.

As shown in Fig. 1, the convection gas pass 10 of a vapor generator is supplied with heating gases which are introduced into the upper portion of the gas pass, with the gases flowing downwardly over horizontally disposed tubular heat exchange elements 11-14. As the heating gases pass downwardly through the gas pass, they flow in parallel flow relationship with a cascading mass of shot which cleans the solid deposits from the exterior of the tubular heat exchange surfaces. In the lower portion of the convection gas pass, the heating gases are separated from the cleaning shot, with the gases discharging through a gas outlet 15 positioned upwardly adjacent the shot accumulation hoppers 16 and 17 positioned beneath the gas pass.

For the effective cleaning of the heat exchange surfaces, the cleaning shot is gravitationally discharged through conduits 20 to shot arrestors 21 from whence it drops to shot distributors 22 positioned above the heat exchange surfaces and is generally scattered throughout the cross-sectional extent of the convection gas pass 10 to fall downwardly through the banks of heat exchange elements in ricocheting relationship to the outer surfaces of the elements. The contact between the cleaning shot and the heat exchange surfaces dislodges the accumulated solids from the heat exchange surfaces maintaining the latter in an eflicient heat exchange condition.

The shot is separated from the heating gases and the entrained solid materials removed from the heat exchange surfaces is discharged downwardly into a hopper 23 which in turn connects with a shot collecting tank 24. Between the hopper and the tank the connecting conduit 25 is provided with a shut-off valve 26 so that the tank 24 may be filled with shot and periodically charged with high pressure fluid to transport the shot from the tank through the connecting lift line 27 to a shot and carrier medium separator 30 positioned above the convection gas pass 10. From the separator 30, which may be of the cyclone type, the separated carrier medium discharges through a pipe 31 while the shot falls into an inverted frusto-conical tank 32 and into a selective distributor 33 to the conduits 20.

As shown in Fig. l, the fluid lift pipe 27 extends upwardly at an angle from the shot collecting tank 24 which is positioned immediately below the convection gas pass. At a selected position to one side of the convection gas pass, the lift pipe 27 extends in an upright direction to a position approximating the upper level of the convection gas pass. Thereafter, the lift pipe is directed upwardly at an angle to discharge in a generally'horizontal direction into the shot and fluid lift medium separator 30. The lift pipe 27 thus is formed of a plurality of straight sections with fittings 34'connecting adjacent sections of the pipe. The arrangement, insofar as the number of fiow'direction changes is concerned, is typical of a shot.

cleaning installation although it will be understood more or less changes in flow direction may be necessary in the fluid lift pipe 27 to meet the physical layout of the heat pipe 35'.

necessary changes in flow direction of' the dense phase mixture of shot and lift medium utilized. Each of the illustrated fittings 34 is constructed for a 45 changein flow direction, althoughit will be. understood that the individual fittings can be constructed' for any desired degree of angularity. In practice, the angularity of the lateral fitting 34 will usually lie in the range of from 30 to 60 with respect to the flow direction of the stream of shot, although the fitting can accommodate an angularity of 90.

As shown in detail in Figs. 2 and" 3, the lateral fitting of the invention is of welded construction, although it could be constructed as a casting. Each fitting includes a straight section 35* of pipe having a cross-section flow oif-setpipe section 36 openingto" the section 35 and having substantially the same cross sectional flow area as In the illustrated embodiment of the invention, the longitudinal'axes'of the sections35 and 36 are ooplanarand' intersect intermediate the length: of the section 35 at an angle of 45.

Both ends of the straightisection 35 are flanged; with one end flange 37 provided'with a cap plate or blank flange38'removably attached to flange'37 at the end of" the pipe section, asby bolts 40, to close-the end'of the fitting 34; The opposite'end of theisection 35 is provided with a blank 'flange' 41 which is eccentrically drilled to form an opening-toaccommodate the'end of a straight section of the pipe 27. The end of an upstream section of the-pipe-27, designated-27A; is inserted into the drilled flange41 and is fixedin position; as by, welding; so as to The not project beyond the inner" face of theflange. flange-41 is attached'to-the'flange 42 of" the section'35, as by bolts, so that the pipe end 27A is positioned on the opposite side of the section 35 from-the lateral pipe section 36. As 'shown; the longitudinal axis of the "section'35-is parallel-tothe longitudinal 'axis'of the pipe'27' including the pipe end 27A;

The end of the section 36 is 1 likewise provided with afiange 43 which is "welded thereto" andis removably attached to a blank flange 44 by bolts'45. The flange 44 is eccentrically drilled to accommodate a" downstream length of the pipe 27, the end portion 27B of which is inserted into the section 36-so that the open end 46 thereof projects into the section 35.

of the-pipe'end 27A, has its' longitudinal axis parallel to the longitudinal axis of the section 36" and With'the wall' thereof in contact, orsubstantially in contact,- along the side of the section 36 closest to'theend 27A'of theupstream pipe length 27.

In an actual construction of'th'efitting described; the" sections 35-and 36 are constructed from'lengths'of6" diameter pipe, and the pipes 27 are in diameter: The eccentric drilling of'the flange'41- is such that"the-inner surfaces of the walls of the pipe 35 andthe-"upstream pipe having the end 27A are substantially in alignment on the side of the "section 35 remote from the"section-3'6.

The eccentric" drilling of the" flange '44 l is such that the outer surface of the wall 'ofthe pipe portion 27B' -are in substantial line contact with-the inner surface" of "the wall-of the section 36;

In the operation ofthe lift line, or transport'system;

incorporating the lateral fit'ting'34',"the*shotis 'passedn In its assembled 7 position the end portion 27B of-thepipe 27, downstream "agesaaee open end 46 of the pipe portion 27B for substantially reduced wear occasioned by movement of the shotin a" i changed direction to the next succeeding fitting 34 in its flowto the separator 30.

While in accordance with the provisions of the statutes I have illustrated and described herein the best form and mode of operation of the invention now known to me, those skilled in the art'will understand that changes may be made in the form of the apparatus disclosed without departing fromthe spirit of the invention covered by my claims, and that certain features of my invention may sometimes be used to advantage with a corresponding use of other features.

What is claimed is:

1. Pressure lift apparatus for particle-form material and a fluent carrier medium comprising a plurality of flow connected substantially straight lengths of lift pipe, said lengths of said lift pipe forming a continuous flow path between a lower inlet end and an upper discharge end' where the latter end is horizontally and vertically spaced from the former end, a plurality of lateral fittings" connecting said lengths of lift pipe, said' lateral fittings each havinga straight tubular section of'greatercross sectional area than said lift pipe forming a pocket therein a in fiow' alignment with the discharge end portion ofa form material passing ther'eth'rough, and an inlet end po'rtion'of a second length of lift pipe positioned intermediate the length of said fitting at an obtuse angle to the first length of'lift pipe and having an opening therein: adjacent and substantially out ofthe direct flow path of the particle-form material discharging from said first length of lift pipe into said fitting.

2. Pressure lift apparatus for particle-formimaterial: and a fluent carrier medium comprising a plurality of fiow connected straight lengths" of lift pipe, a lateral" fitting connectingadjacent lengths of said lift pipe toform a continuous flow path between a lower inlet' end portion and an upper discharge end portion wherethe latterend'ishorizontally and vertically spaced from the former" end, said lateral fitting having a straight tubular section of greater. cross-sectional area thansaid lift pipe discharge end portion of a first length of lift pipe to maintain'a'bed of the particle-form material passing therethrough, and'an inletend portion of a second length of thetbedawith the shotithereaftertibeingadiverted intosthe:

lift pipe positioned intermediate the length of said fittin'g at an'obtuse angle to the axis of said first length of'lift intersecting-intermediate the length of said straight section i and atan acuteangle thereto, means ;for connecting.the dischargeendoftone of saidlift pipes tothe straight: sectionrof-said fitting with the axis of said lift pipeparallel to the .axis of the straight section of said .fitting'and' spaced on the side of'the fitting opposite from said off-take section, andmeans for positioning the .inlet endportion-of the second of said lift pipe lengths in the off-take section of saidfitting, the axes of saidsecondpipe lengthand'the olf-take section'ofsaid fitting being parallel and the walls thereof'fbeing substantially in contact'adjacent the" charge-endof said first named lift pipe length, the open end portion of said second lift pipe length terminating 'withi'n the straight section of said fitting whereby an obtuse' angle is formed'between the axes offloW-of ma terial through said-fitting of said lift pipes to the straight section of said fitting with i the axis of said lift pipe parallel to the axis of the straight section of said fitting and spaced on the side of the fitting opposite from said ofi-take section, and means for positioning the inlet end portion of the second of said lift pipe lengths in the off-take section of said fitting, the axes of said second pipe length and the ofi-take section of said fitting being parallel and the walls thereof being substantially in contact adjacent the discharge end of said first named lift pipe length, the open end portion of said second lift pipe length terminating out of the first flow path of the particle-form material discharging into said fitting whereby an obtuse angle is formed between the axes of flow of material through said fitting.

References (Zited in the file of this patent UNITED STATES PATENTS 2,676,142 Crowley Apr. 20, 1954 2,799,673 Berg May 31, 1955 FOREIGN PATENTS 278,858 Germany July 18, 1913 501,591 Germany Jan. 9, 1927 295,984 Switzerland Apr. 1, 1954 

